Lighting designers evaluate the quality of a recessed light fixture based in part on how well the fixture distributes light on a wall adjacent to the fixture. This type of fixture is typically referred to as a downlight wall-wash. Ideally, the lighting designers strive to achieve uniform light distribution on the wall and smooth transition down the wall toward the floor. For example, multiple wall washers are installed next to each other to eliminate arch-type of light distribution (also known as “scallops”) and to create a uniform wall pattern horizontally and vertically across the wall, with no variation in footcandles.
Wall-wash reflectors have been traditionally designed with a reflector shape intended to support a multi-directional light source in which light is generated in all directions, e.g., incandescent, high-intensity discharge (HID), and compact-fluorescent (CFL) light sources. For example, traditional reflectors had a parabolic shape in which a window was cut out and replaced with a re-directing partial parabolic kicker. The light source was located at the center of the parabola and the kicker was located on a side of the reflector. The result was that a portion of the light was directed towards the floor and a portion of the light was directed up toward the wall.
As light-emitting diodes (“LEDs”) have become a viable source for downlights, manufacturers have continued to design wall-wash reflectors using the traditional parabolic-shape approach. Specifically, the LED light source was moved from the center of the parabola to the top of the parabola, and additional side reflective kicker was included. The result, however, was that the majority of the light was reflected toward the wall into a small circular “hot spot” pattern.